Welcome to my new neoclassical lesson called "Triplet Etude". As the title says - we are going to focus on triplets.

"Whereas normally two quarter notes are the same duration as a half note, three triplet quarter notes total that same duration, so the duration of a triplet quarter note is 2/3 the duration of a standard quarter note. Similarly, three triplet eighth notes are equal in duration to one quarter note. If several note values appear under the triplet bracket, they are all affected the same way, reduced to 2/3 their original duration. The triplet indication may also apply to notes of different values, for example a quarter note followed by one eighth note, in which case the quarter note may be regarded as two triplet eighths tied together" - Wikipedia